Hi zemirah and flomme,
Go to Settings -> eShop (this will take you to your eShop settings page.
Once there, find the Screen Options button somewhere on the top right area. Click it. When you click it, an area will appear above the Screen Options button.
There you should see what Esmi is referring to. I am pretty sure, you will have the radio button 1 is selected for Number of Columns under the Screen Layout heading. Change it to 2, then the option to change the eShop status from Testing to Live will appear on the right hand column.
Hope it helps